The Dafangguang-rulaixingqiweimizang-jing, a Chinese Buddhist canon belonging to the Huayn group, has been recognized that it had been lost in the far past, in spite of once in existence for certain. We recently had the fortune to discover it in the Tripitaka preserved at the Nanatsudera temple in Nagoya. Our study has been carried out with the final purpose to investigate this Nanatsudera text(=N) thoroughly and clear up its historical significance.The main fruits of the study are as follows ; (1) N was probably written by a monk named Renjobo in the later harf of the 12th century. It is very valuable, though we have to deal with it carefully, because we can not help finding some miswritings in it. (2) It is almost identified with the chapter of Rulaixingqi-pin of the Huayn-jing (60 vols.). (3) The original text of it seems to have been picked out from the Huayn-jing translated by Buddhabhadra, edited as a single canon, and spread over the society. (4) N world be descended from the original one.